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<FONT color="green">001</FONT>    // Copyright 2008 Waterken Inc. under the terms of the MIT X license found at<a name="line.1"></a>
<FONT color="green">002</FONT>    // http://www.opensource.org/licenses/mit-license.html<a name="line.2"></a>
<FONT color="green">003</FONT>    package org.waterken.syntax;<a name="line.3"></a>
<FONT color="green">004</FONT>    <a name="line.4"></a>
<FONT color="green">005</FONT>    import java.io.EOFException;<a name="line.5"></a>
<FONT color="green">006</FONT>    import java.io.IOException;<a name="line.6"></a>
<FONT color="green">007</FONT>    import java.io.Reader;<a name="line.7"></a>
<FONT color="green">008</FONT>    <a name="line.8"></a>
<FONT color="green">009</FONT>    /**<a name="line.9"></a>
<FONT color="green">010</FONT>     * A text reader that keeps track of the current line and column number, as well<a name="line.10"></a>
<FONT color="green">011</FONT>     * as the most recent character {@linkplain #read read}.<a name="line.11"></a>
<FONT color="green">012</FONT>     */<a name="line.12"></a>
<FONT color="green">013</FONT>    public final class<a name="line.13"></a>
<FONT color="green">014</FONT>    SourceReader {<a name="line.14"></a>
<FONT color="green">015</FONT>        private final Reader in;<a name="line.15"></a>
<FONT color="green">016</FONT>        private       int line; <a name="line.16"></a>
<FONT color="green">017</FONT>        private       int column;<a name="line.17"></a>
<FONT color="green">018</FONT>        private       int head;<a name="line.18"></a>
<FONT color="green">019</FONT>        <a name="line.19"></a>
<FONT color="green">020</FONT>        /**<a name="line.20"></a>
<FONT color="green">021</FONT>         * Constructs an instance.<a name="line.21"></a>
<FONT color="green">022</FONT>         * @param in    underlying character stream<a name="line.22"></a>
<FONT color="green">023</FONT>         */<a name="line.23"></a>
<FONT color="green">024</FONT>        public<a name="line.24"></a>
<FONT color="green">025</FONT>        SourceReader(final Reader in) {<a name="line.25"></a>
<FONT color="green">026</FONT>            this.in = in;<a name="line.26"></a>
<FONT color="green">027</FONT>            line = 0;       // position (0, 0) means nothing has been read yet<a name="line.27"></a>
<FONT color="green">028</FONT>            column = 0;<a name="line.28"></a>
<FONT color="green">029</FONT>            head = '\n';    // will put the stream at (1, 1) on first read operation<a name="line.29"></a>
<FONT color="green">030</FONT>        }<a name="line.30"></a>
<FONT color="green">031</FONT>        <a name="line.31"></a>
<FONT color="green">032</FONT>        /**<a name="line.32"></a>
<FONT color="green">033</FONT>         * Gets the line number of the {@linkplain #getHead head} character.<a name="line.33"></a>
<FONT color="green">034</FONT>         */<a name="line.34"></a>
<FONT color="green">035</FONT>        public int<a name="line.35"></a>
<FONT color="green">036</FONT>        getLine() { return line; }<a name="line.36"></a>
<FONT color="green">037</FONT>        <a name="line.37"></a>
<FONT color="green">038</FONT>        /**<a name="line.38"></a>
<FONT color="green">039</FONT>         * Gets the column number of the {@linkplain #getHead head} character.<a name="line.39"></a>
<FONT color="green">040</FONT>         */<a name="line.40"></a>
<FONT color="green">041</FONT>        public int<a name="line.41"></a>
<FONT color="green">042</FONT>        getColumn() { return column; }<a name="line.42"></a>
<FONT color="green">043</FONT>        <a name="line.43"></a>
<FONT color="green">044</FONT>        /**<a name="line.44"></a>
<FONT color="green">045</FONT>         * Gets the last {@link #read read} character, or {@code -1} for EOF.<a name="line.45"></a>
<FONT color="green">046</FONT>         */<a name="line.46"></a>
<FONT color="green">047</FONT>        public int<a name="line.47"></a>
<FONT color="green">048</FONT>        getHead() { return head; }<a name="line.48"></a>
<FONT color="green">049</FONT>        <a name="line.49"></a>
<FONT color="green">050</FONT>        /**<a name="line.50"></a>
<FONT color="green">051</FONT>         * all Unicode line terminators<a name="line.51"></a>
<FONT color="green">052</FONT>         */<a name="line.52"></a>
<FONT color="green">053</FONT>        static public final String newLine = "\n\r\u0085\u000C\u2028\u2029";<a name="line.53"></a>
<FONT color="green">054</FONT>    <a name="line.54"></a>
<FONT color="green">055</FONT>        /**<a name="line.55"></a>
<FONT color="green">056</FONT>         * Gets the next character in the stream.<a name="line.56"></a>
<FONT color="green">057</FONT>         * @throws EOFException attempt to read past EOF<a name="line.57"></a>
<FONT color="green">058</FONT>         * @throws IOException  any I/O problem<a name="line.58"></a>
<FONT color="green">059</FONT>         */<a name="line.59"></a>
<FONT color="green">060</FONT>        public int<a name="line.60"></a>
<FONT color="green">061</FONT>        read() throws EOFException, IOException {<a name="line.61"></a>
<FONT color="green">062</FONT>            if (-1 == head) { throw new EOFException(); }<a name="line.62"></a>
<FONT color="green">063</FONT>            <a name="line.63"></a>
<FONT color="green">064</FONT>            final int next = in.read();<a name="line.64"></a>
<FONT color="green">065</FONT>            if (-1 == newLine.indexOf(head) || ('\r' == head &amp;&amp; '\n' == next)) {<a name="line.65"></a>
<FONT color="green">066</FONT>                column += 1;<a name="line.66"></a>
<FONT color="green">067</FONT>            } else {<a name="line.67"></a>
<FONT color="green">068</FONT>                line += 1;<a name="line.68"></a>
<FONT color="green">069</FONT>                column = 1;<a name="line.69"></a>
<FONT color="green">070</FONT>            }<a name="line.70"></a>
<FONT color="green">071</FONT>            return head = next;<a name="line.71"></a>
<FONT color="green">072</FONT>        }<a name="line.72"></a>
<FONT color="green">073</FONT>        <a name="line.73"></a>
<FONT color="green">074</FONT>        /**<a name="line.74"></a>
<FONT color="green">075</FONT>         * Closes the text stream.<a name="line.75"></a>
<FONT color="green">076</FONT>         * @throws IOException  any I/O problem<a name="line.76"></a>
<FONT color="green">077</FONT>         */<a name="line.77"></a>
<FONT color="green">078</FONT>        public void<a name="line.78"></a>
<FONT color="green">079</FONT>        close() throws IOException {<a name="line.79"></a>
<FONT color="green">080</FONT>            if (-1 != head) {<a name="line.80"></a>
<FONT color="green">081</FONT>                column += 1;<a name="line.81"></a>
<FONT color="green">082</FONT>                head = -1;<a name="line.82"></a>
<FONT color="green">083</FONT>            }<a name="line.83"></a>
<FONT color="green">084</FONT>            in.close();<a name="line.84"></a>
<FONT color="green">085</FONT>        }<a name="line.85"></a>
<FONT color="green">086</FONT>    }<a name="line.86"></a>




























































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